424 Small Block on the dyno.

[IQ52]

Yesterday we finally got the 424/360 back on the dyno. We built the engine in 2015 with ProComp/RaceMaster aluminum heads and just switched to a set of Indy LAX heads we've been toying with since 2010.

950 cfm TrickFlow 4150 carburetor
Edelbrock Super Victor single plane
Our ported Indy LAX heads with Chevy stud mounted rockers by Scorpion
Custom solid roller from Comp Cams
MRL roller lifters
BPE stroker assembly
10.83 compression
91 octane from the Stinker Station

Best results?

481 lb-ft @ 3,000 rpm start of pull
572 lb-ft @ 4,800 rpm
603 hp @ 6,300 rpm
Still making 594 hp @ 6,600 rpm where we shut it off.

A real beauty ain't she?

 

[747mopar]

Impressive for even a BB but without the extra size and weight.

 

[super-bee_ski]

Wow
Great build!
Using the Super Victor I would guess that it is for Horse Power at the "Higher RPM" range...

Did you see better numbers from the Indy Heads?

 

[IQ52]

Wow
Great build!
Using the Super Victor I would guess that it is for Horse Power at the "Higher RPM" range...

Did you see better numbers from the Indy Heads?

We got much better flow numbers from the Indy iron heads we ported than the ProComp heads we ported. But because of the small cross section of both heads, the 424ci chokes around 6,200 rpm, and we only gained a couple of horse power up top, from 601 hp to 603 hp. But we gained 20-40 lb-ft of torque in the 3,000-4,500 rpm range and 10-20 lb-ft of torque in the 4,600-5,600 rpm range.

 

[mmissile]

Nice.

 

[dieseldazzle]

Stock Chrysler block?

 

[IQ52]

Stock Chrysler block?

10-4

 

[dieseldazzle]

10-4

Time for a small plate on it

 

[1967coronet440]

Yesterday we finally got the 424/360 back on the dyno. We built the engine in 2015 with ProComp/RaceMaster aluminum heads and just switched to a set of Indy LAX heads we've been toying with since 2010.

950 cfm TrickFlow 4150 carburetor
Edelbrock Super Victor single plane
Our ported Indy LAX heads with Chevy stud mounted rockers by Scorpion
Custom solid roller from Comp Cams
MRL roller lifters
BPE stroker assembly
10.83 compression
91 octane from the Stinker Station

Best results?

481 lb-ft @ 3,000 rpm start of pull
572 lb-ft @ 4,800 rpm
603 hp @ 6,300 rpm
Still making 594 hp @ 6,600 rpm where we shut it off.

A real beauty ain't she?

View attachment 418774

Nice job

 

[Budnicks]

Damn nice #'s IQ52

extremely respectable #'s Jim, congrats

was it a 4" stroke ?
how did you get the 424ci, strange displacement
Am I missing something ?, maybe I'm just losing it
is it a bigger bore 340 block ?
& crank turned down for the 318/340 mains ?

Just curious

4" x 4" bore x 4" stroke x 8 x .7854 = 402 ci
0.060" over & a 4" stroke I get 414ci
0.090" over & a 4" stroke I get 420.42ci
{4.10" bore a 340 @ 0.060" over & a 4" stroke I get 422ci}
0.030" over & a 4.15" stroke I get 423ci
0.060" over & a 4.15" stroke I get 429ci
4" std. bore & a 4.25" stroke I get 427ci

 

[IQ52]

And the big deal is Mr. Nosey? Bwaaaah, ha, ha, ha!

4.042" bore by 4.125" stroke equals 423.45. I know how to round a number off but I like the sound of 424 better than 423.

 

[Budnicks]

And the big deal is Mr. Nosey? Bwaaaah, ha, ha, ha!

4.042" bore by 4.125" stroke equals 423.45. I know how to round a number off but I like the sound of 424 better than 423.

wait 4.042 x 4.042 bore x 4.125 stroke x 8 x .7854 = 423.44
Thanks Jim, I was wondering what the heck...

edited;
kind of thought it had to be a 4.15 stroke...
BUT; I see it is a 4.125 stroke, that's a tad bit different stroke,

is that about the biggest stroke that can fit ?
was it an offset grind ?
What rods ?
what size journals ?
what camshaft ?

Carry on, just me being nosey & my uncanny morbid curiosity,
was getting the best of me

any other specs/fine details you can share

 

[Hemirunner]

Nice! What are the cam specs?

 

[IQ52]

I bought a Bloomer Performance Engineering stroker kit with a 6.200 Chevy rod with the Chevy journal. He has a 4.250 stroker crank also.

The camshaft, yeah, well, okay..........solid roller......

289/291 @ .020" tappet lift
258/260 @ .050
.425/.430 lobe lift
110 LSA on a 107 ICL

Right now we are running 1.5 rockers and the heads are flowing....

73/58 cfm @ .100"
145/124 cfm @ .200"
206/176 cfm @ .300"
253/214 cfm @ .400"
275/226 cfm @ .450"
290/236 cfm @ .500"
301/242 cfm @ .550"
303/248 cfm @ .600"
297/253 cfm @ .650"

It's a pretty trick head but we are still stuck with a small cross sectional area by the pushrod pinch that chokes the engine around 6,200 rpm.

 

[69 GTX]

Very nice Jim, that'd be good in a Old Dodge Truck ;0)

 

[Budnicks]

Thanks Jim/IQ52

 

[IQ52]

Dropped the pan and installed our windage tray and crank scraper. 611 HP @ 6,300 rpm and 600 or more horsepower from 6,100-6,600 rpm.

 

[69 GTX]

So the windage tray/scraper was good for about 8 hp?

 

[IQ52]

So the windage tray/scraper was good for about 8 hp?

Yes, that was the only change.

 

[440+6]

Impressive for sure, good job!